1. Field of the Invention
The present invention relates to a shock absorbing type steering column apparatus for an automobile.
2. Related Background Art
In the event of a collision of an automobile, subsequent to a so-called primary collision that the car collides against another car, there happens a so-called secondary collision that a driver collides against a steering wheel. For the purpose of protecting a life of the driver by minimizing an impact on the driver when the secondary collision happens, there has generally been adopted a system in which a steering shaft with the sheering wheel being fixed to one side end thereof is constructed as a so-called collapsible steering shaft of which an entire length is reduced when a strong impact is applied, and a steering column through which the steering shaft is inserted is structured as a shock absorbing steering column.
What is known as a shock absorbing steering column apparatus used for the purpose described above, is disclosed in, e.g., Japanese Utility Model Laid-Open Publication Nos. 63-76578 and 5-75057. The shock absorbing steering column apparatus, which has hitherto been known by the disclosures in those Publications, has a shock absorbing member provided between the steering column and a member for fixation to a car body etc. Upon the secondary collision, the shock absorbing member permits while being plastically deformed the steering column to displace forward, thereby relieving the impact exerted on the driver's body colliding against the steering wheel.
The conventional shock absorbing steering column apparatus explained above involves the use of the shock absorbing member independently of the steering column, which makes laborious all of parts manufacturing, a parts management and an assembly work and inevitably leads to a rise in costs.